Fusible link



Aug. A11, 192s. M. K. HOPKINS FUSIBLE LINK Original Filed April 23. 1919Reissued ug. 1l, 1925.

.UNITED STATES PATENT OFFICE.

NORTON x. HOPKINS, or cHIcAefo,l ILLINOIS, assIGNoR 'ro moi/IVN L.KENNEDY, o

CHICAGO, ILLINOIS.

FUSIBLE LIN-K'.

rig'inal No'. 1,356,919, dated October 26, 1920, Serial No. 292,142,filed April 23, 1919. Application forV reissue filed October 26, 1922.Serial No. 597,184.

To all whom t may concern.'

Be it known that I, M-on'roN K. HorKiNs, acitizen of theI United States,residing at Chicago, in the county of Cook and State of Illinois, haveinvented certain new and useful Improvements in Fusible Links, of whichthe following is a description.

My invention belongs to that general class of devices known as fusiblelinks, which under normal conditions are adapted to securely connectycooperating parts or mechanisms, but under abnormal conditions willrelease to allow the parts to separate. Such devices are used for manypurposes, but are particularly desirable and very generally used in`connection 'with automatic sprinkler heads, and my improved link ispeculiarly adapted for that use, but obviously may be used whereverfound desirable.

The invention has among its objects the production of a device of thekind described that is simple and economical in construction, andthoroughly efficient and satisfactory in use.

To this end, my invention consists in the novel construction,arrangement and combination of parts herein shown and described, andmore particularly pointed out in the claims.

In the drawings, wherein like reference characters indicate like orcorresponding parts,

Figure l is a face view of my improved link assembled;

Figure 2 is an edge view of the same before the solder is applied;

Fig. 3 is a sectional view on Fig. l.;

Fig. 4 is a transverse sectional view on lin-e 4 4 of Fig. l;

Fig. 5 is a sectional view similar to Fig. 3, enlarged to more clearlyshow the operating portion of the device;

Fig. 6 is a vertical central sectional view, illustrating the operationas the parts are separated;

Fig. 7 is an inside. face view illustrating a slight modification; and

Fig. 8 is a central vertical section on line 8-'-8 of Fig. 7 when the`latter and associated arts are assembled.

Referring to the 'several drawings, 1-2 are cooperating Amating .platesadapted to be line 3-3 of placed face to face with the connectin A.loopsextending in opposite directions. ne .of the plates, as 1 has a pocketor recess 3, formed therein, which at one end, as shown in Figs. l to 6,is slightly depressed to re ceive an anti-friction 'roller 4 extendingtransversely the same. The approximate wall of the pocket or depressionis preferably beveled or inclined as at 13. The 0pposite plate has acooperating recess 6 formed therein substantially registering with therecess 3, the two providing for the reception of a key member, generallyindicated by the reference character A. The key has a thickened portionas at 8, substantially to the extent that it will loosely fill the cellformed between the two plates at that point. An extending thinned por'-tion 9 extends over the anti-friction roller 4, and lies upon the innerwall of the plate as at 10. A shoulder 11 formed between the thickenedportion and thethin or eX- tending tongue 9 of the key A, rests back ofthe anti-friction roller 4, as cle-arly shown in Figs. 3 and 5, and ispreferably provided with an outwardly beveled or inclined part 5,connecting with the relatively straight narrow shoulder portion 5a. Inthe form of plate shown, the two plates are stamped from suitable metal,the Jformation of the recess or cell 3 being indicated on the oppositeside. of the plate 1. Suitable studs l?. are preferably provided uponthe meeting faces of the plates so as to slightly space the two andpermit the even distribution. of the solder therebetween. When the partsare assembled and in use, the pull is in the direction indicated by thearrows in Figs. 2, 3, 6 and 8.

In assembling the plates, the anti-friction roller 4 is dropped intoposition, and the key A placed thereon, with the shoulder 11 back of theroller, the roller and key loosely but somewhat snugly fitting the cellor pocket thus formed. The other plate is then placed in position andthe whole secured together by a suitable quality of solder.

It will be seen that Ywith the pull in "the direction indicated by thearrows, the loosening of the solder will cause the shoulder 11 to ride`over the anti-friction roller 4, the front end 9 of the key bearingupon the face of 'one plate, ywhile :the rear wall of the other 1between the parts, though slight.

plate engages the corner of the key, as clearly shown inY Fig. 6. Thisaction causes the forcible and instantaneous separation of the twoplates.

In the form shown in Figs. 7 and 8, the same construction is found, withthe exception that the anti-friction roller 4 is not seated in adepression in the cell. The rear wall of the cell, as at 13, is inclinedas before to provide but a slight retaining corner, and the face of thekey as at 14 is also beveled or inclined, the two being so constructedas to provide positive engagement Upon the solder releasing, the rearwall of the cell in the plate 2 will engage the corner 15 of the key,serving to slightly lift the same, when the inclined face on the keywill ride over gathers upon vIn other words,

the roller and the key will slip over the wall, the front extension 9operating in the same manner as is shown in Fig. 6. The action of theroller is slightly less restricted in the latter form than in theformer.

One of the difficulties of a fusible link used for this purpose iscaused by corroding between the meeting edges of the plate about themargin. Also in some cases calcimine the plates and interferes withtheir proper action. To guard against the objections above noted, Iprefer to offset the plates in relation to each other to provide anextending margin, as clearly shown in Figs. 4 and 7. The width of thisextending margin may be varied as desired, but it preferably extendsclear about the outer edges of the links, as well as at all exposedpoints, as at the opening 17 and the cooperating indentation 18. Thismay be readily accomplished by slightly oifsetting one plateI withrelation to the other, as indicated in the several iigures.

The entire deviceas thus described possesses the necessary positiveengagement of the parts to reliabl7 sustain the strain in the pullingdirection under all normal conditions, and at the same time, when thesolder softens sufficiently to release the parts, they are quickly andreliably disengaged to permit the separation of the connected parts heldtogether by the link.

It will be appreciated that by reason of the inclined surfaces on thekey and the wall surrounding the recess, the cooperating engagingsurfaces are slight, but amply sufIicient to take the strain of? of thesolder, but upon the solder melting, which allows the plates to separateslightly, the inclined faces in cooperation with the roller tend tocause the plates to quickly separate. Should the roller not release asquickly as the rest of the device as by some solder getting under theroller, the key nevertheless would quickly move outwardly by reason ofthe engagement of the inclined face with the roller. while upon theassembling of the parts together with suitable solder, they will bepromptly retained in position, upon the melting of the solder, thelongitudinal movement of the cooperating plates one upon the other, willdisengage the key and the engagement of the inclined` faces with theroller will accelerate the separation of the plates.

Having thus described my invention, it is obvious that variousimmaterial modifications may be made in the same without departing fromthe spirit of my invention; hence I do not wish to be understood aslimiting myself to the exact form, construction, arrangement andcombination of parts herein shown and described, or uses mentioned.

I claim* 1. In a fusible link and in combination, cooperating matingparts adapted to be placed face to face and constructed to provide a keyway between them, an anti-friction device transversely vpositioned inthe key way adjacent to one wall thereof, and a cooperating key adaptedto be placed in the key way with a part extending back of and in contactwith the anti-friction device, with an extension passing over theantifriction device and resting upon the wall of the plate beyond thesame, whereby upon assembling the parts together with suitable solder,they will be firmly retained in position, but upon melting the solder,they will be quickly and positively disengaged.

2. A fusible link comprising cooperating mating plates adapted to beplaced face to face and constructed to provide a key way between them,an antifriction roller transversely positioned in the key way adjacentto one wall thereof, in combination with a cooperating key adapted to beplaced in the key way with a part extending back of and in contact withthe anti-friction device, with an extension passing over the same andresting upon the wall of the plate beyond it, the contacting wall of thecell with the anti-friction device and of the shoulder of the keycontacting therewith being inclined to facilitate the riding of the keyover the anti-friction device.

3. In a fusible link and in combination, cooperating mating partsadapted to be placed face to face and constructed to provide a key waybetween them, said key way near one wall thereof being depressedtransversely to receive an anti-friction roller, an anti-friction rolleradapted to be placed in said depression, a cooperating key adapted to beplaced in the key way, provided with a part extending back of and incontact with the anti-friction roller, with an extension passing overthe anti-frictio-n roller and resting upon the wall of the plate beyondthe same, said key being provided' at its meeting point with theanti-friction roller with an inclined face, facilitating the readyriding of the key over the roller.

v4. In a device of the. kind described and in combination, cooperatingmating parts adapted to be placed face to face and corrstructed toprovide a key way between them, the key way being so positioned thatwhen the parts are assembled said plates will be offset slightly inrelation to one another, permitting the edges toproject beyond oneanother to provide a solder channel, anti friction means arrangedtransversely withthe key way adjacent to one wall thereof, a cooperatingkey adapted to be placed in the'key way with a part extending back ofand in contact with the anti-friction means, with' an extension passingover the antifriction meansy and resting upon the wall of the plate beond the same, the contacting wall of the ey way with the anti-frictionmeans being inclined to facilitate the ready riding of the key vover theanti-friction means.

5. A fusible link construction comprising cooperating members adaptedwhen released to move relatively lengthwise, said members each beingprovided with akey receiving portion opening inwardly from the innerface thereof and which whenthe members are assembled forms a key way, incombination with a key fo-rmed to fit within the key way, one of saidparts being provided with an inclined face portion, and said key havinga part projecting over the inner face of one of the membe s beyond thekey-receiving portion.

6. A fusible link construction comprising cooperating members adaptedwhen released to move relatively lengthwise, said members each beingprovided with a key receiving portion opening inwardly vfrom the innerface thereof and which when the inemb'ers are assembled form a key way,in combination with akey formed to fit within the key way, said key andone of said key receiving portions having inclined faces, and said keyhaving a part projecting over the inner face of one of the membersbeyond the keyreceiving portion. y

7. A fusible link construction comprising cooperating members adaptedwhen released` to move relatively lengthwise, said members each beingprovided with a key receiving portion opening inwardly from the innerface thereof and which when the members are assembled forms a key way,in combination with a key formed to fit within the key way and providedwith a part to extend beyond the key receiving portion in one of themembers over the inner face thereof, the wall of the key receivingportion o-f one of the members having an inclined face portion.

8. A fusible link construction comprising cooperating members adaptedwhen released to move relatively lengthwise, said members each beingprovided with a key receiving portion opening inwardly from the innerface thereof and when sembled forming a key way, in combination with acooperating key formed to fit within the key way and provided with apart to extend beyond the key receiving portion in one of the membersover the inner face thereof, said key member having an inclined faceportion, and the wall of the recess of one of the members having aninclined face portion.

V9. A fusible link construction comprising cooperating members adaptedwhen released to move relatively lengthwise, said members each beingprovided with a key receiving portion opening inwardly from the innerface thereof and when the members are assembled forms a key way, incombination with a cooperating key formed to fit within the key way andprovided with a part to extend beyond the key receiving portion in oneof the members over the inner face thereof, said key member havinginclined face portions at both ends, and the wall o-f the recess of oneof the members having an inclined face portion.

10. A fusible link. construction comprising cooperating members adaptedwhen released to move relatively lengthwise, said members each beingprovided with a key receiving portion opening inwardly from the innerface thereof and which when the members are assembled forms a key way,the key receiving portions of the members being the members are as-Yrelatively shallow and of substantially equal depth, in combination witha cooperating key formed to iit within the key way and provided with apart to extend beyond the key receiving portion in one of the menibersover the inner face of said member, the key intermediate its ends havingan inclined portion and the adjacent portion of the key opening having acooperating inclined portion.

1. A fnsible link construction comprising cooperating members adaptedwhen released to move relatively lengthwise, said members each beingprovided with a key receiving portion opening inwardly from the innerface thereof and which when the members are assembled forms a key way,in combination with a cooperating key formed to fit within the key wayand provided with a part to extend beyond the key receiving portion inone of the members over the inner face thereof, said key member havingan inclined face portion.

12. A fusible link construction comprising cooperating members adaptedwhen released to move relatively lengthwise, said members each beingprovided with a key receiving retaining face thereof and which when themembers are assembled forms a key Way, in combination with aco-operating key formed to fit Within the key Way and provided with apart to extend beyond the key receiving portion in one of the membersover the inner face thereof, said key member having inclined faceportions at both ends.

13. In a fusible link and in combination, cooperating mating platesadapted to be placed face to face and constructed with a key Way betweenthem, said key Way being of smaller area in one of said plates than. inthe other, and a cooperating key conforming to the key way with thesection extending into the smaller area forming a shoulder with aninclined face and a slight retaining Wall, the approximate Wall of thekey Way being also formed with an inclined face and Wall to facilitatethe releasing of the key from the key Way.

14. In a fusible link and in combination, cooperating plates adapted tobe placed face to face and constructed with a key Way bet-Ween them,said key Way being of smaller area in one of said plates than the other,and a cooperating key conforming to the key Way With the sectionextending into the smallerl area forming a shoulder with an inclinedpart and a vertical part, the approximate Wall of the key Way formedWith a cooperating inclined part and vertical part, whereby is provideda positive normal connection and on slight movement, a quick release.

15. A device of the kind described comprising mating plates eachprovided With a recess which when the parts are assembled forms akeytvay, in combination with a cooperating key formed to loosely litWithin the keyway and provided With a part to extend beyond the recessin one of the plates over the face of the plate.

16. A fusible link comprising cooperating members adapted when releasedto move relatively lengthwise, said members each being provided With akey-receiving portion opening inwardly from the inner face of saidmembers and which When the members are assembled forms a keyway, incombination with a cooperatingkey formed to loosely t Within the keywayand provided With a part to extend beyond the key-receiving portion inone of the members over the inner face of said member.

17. A fusible link comprising opposed members, the said members eachhaving a recessed part which when brought into registration provides akeyway, in combination with a cooperating key formed to loosely litWithin the keyivay and provided with a part to extend beyond the recessin one member over the inner surface of said last named member.

18. A fusible link comprising two mating plates each provided With meanson one endV to engage a co-operating part, the said engaging endsextending in opposite directions when the parts are assembled, the saidplates each having formed therein a depression Which When the parts areassembled forms a keyway, one of said depressions being of larger areathan the other, the smaller depression being provided on an end WallWith an angular part and an inclined part extending from said angularpart to the face of the plate, in combination With a key, on one sideformed to loosely seat in the smaller depression, and provided With anangular part and inclined edge portion, said last named side of the keyhaving a part. thereof lying on the face of the corresponding plate.

19. A device of the kind described comprising mating plates eachprovided With means on one end to engage a cooperating part, saidengaging ends extending in opposite directions when the parts areassembled, the said plates each having formed therein a depression whichwhen the parts are assembled forms a substantially L-shaped keyvvay, thesmaller part of the keyWay being provided on its end Wall with a partextending substantially at right angles to the face of the plate alimited distance, and With an inclined section extending therefrom tothe face of the plate, in combination With an L- shaped key formed toloosely seat in the key- Way, the arm of the key forming a rightangularextension, said right-angular extension having an inclined edge portion.

In testimony whereof I hereunto affix signature in the presence ofMORTON Witnesses CHAs. J. MAxoY, THEO. S. VALENTINE.

my two Witnesses. K. HGPKINS.

